In a disk memory device, in a case where a deficiency due to a flaw or the like exists on a disk memory medium on which data are recorded, when the data written in a sector including the deficiency portion is read, a read error sometimes occurs. Further, when the deficiency portion exists in a servo signal part on the disk memory medium, which part has previously been recorded for positioning a head structure, the deficiency portion adversely affects the accuracy of the head structure positioning and, thus, a position of a target sector from/into which data is to be read or written can not be specified. In this case, a read error or a write error for the target sector sometimes occurs.
Accordingly, since the sector on the disk memory medium where an error occurs in writing or reading is unreliable, when the disk memory device reads or writes data, generally, such sector is skipped or substituted by a spare sector, so that the sector where the error occurs is not used.
Conventionally, in order to perform the substitution process or the like for the error portion on the disk memory medium, a process of checking a defect position on the disk memory medium is performed by conducting a test of writing and reading data into/from all sectors on the disk memory medium to previously judge the existence of a read or write error.
In the conventional process of checking the defect position on the disk memory medium, even when writing/reading fails once in the writing/reading test, it is not judged that the sector has an error if data can be normally written or read after several times of recovery process.
For example, in the disk memory device, when a deficiency due to a flaw or the like exists on the disk memory medium on which data are to be recorded, and a read error occurs in reading the data which are written in a sector including the deficiency portion, the disk memory device generally attempts error correction by a data correction process such as ECC correction, or performs an error recovery process of attempting several times of data reading from the sector where the read error occurs until the data are normally read. Also, when the deficiency portion exists in the servo signal part and adversely affects the accuracy of the head structure positioning and, thus, the position of the target sector from/into which the data are to be read or written cannot be specified, the disk memory device usually performs a head structure positioning recovery process of attempting several times of position specifying process until the position of the target sector is specified.
When the conventional disk memory device can normally read or write data from/into the sector on the disk memory medium by executing the above-described recovery process, it is not judged that the sector has an error even when the data reading or writing requires a longer time than usual.
However, when the above-described disk memory device is employed for recording/reproducing AV data, it is required to read or write required data from/on the disk memory medium of the disk memory device within a prescribed time so as to reproduce video without interruption or record data without lack of frames. Accordingly, when the disk memory device is employed for recording/reproducing AV data, it is required to assure that the reading or writing process is finished within the prescribed time, and in addition, that the stored data are normally read. In the conventional sector defect determining method, it is impossible to determine a position which requires an access time longer than the prescribed time, as defective, and thus when data are recorded or reproduced in/from the position, there occurs lack of data at the recording or lack of frame at the reproduction.
The present invention is made to solve the above-described conventional problems and has for its object to provide a disk memory device which is able to reproduce videos without interruption or record pictures without lack of frame when the disk memory device is employed for recording/reproducing AV data, a disk memory device defect determining method, and a recording medium storing a program for processing the determining method by a computer.